Liquid pumps



July 1, 1969 R. T. J. SKINNER LIQUID PUMPS Filed May 1, 1967 United States Patent ()1 3,452,679 Patented July 1, 1969 3,452,679 LIQUID PUMPS Robert Thomas John Skinner, Kenilworth, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England Filed May 1, 1967, Ser. No. 635,051 Int. Cl. F04d 3/02 US. Cl. 10396 3 Claims ABSTRACT OF THE DISCLOSURE A liquid pump including a pumping rotor which is, rotatable in a chamber in a body to pump liquid from the chamber, the pump being provided with means for producing a flow of filtered liquid from between the adjacent faces of the rotor and the body into the chamber so as to prevent dirt and grit from the liquid in the chamber entering between the adjacent faces of the rotor and the body.

This invention relates to liquid pumps, of the kind comprising a body having therein a chamber, a rotor having peripheral blades, rotatable within said chamber, a liquid inlet passage through which liquid is supplied to said chamber, and an outlet passage through which liquid is pumped from said chamber by rotation of said rotor.

It is an object of the invention to provide a pump of the kind specified wherein the wear of the adjacent faces of the body and the rotor is minimised, in the event that the liquid being pumped contains extraneous material such as dirt or grit.

According to the invention in a pump of the kind specified the faces of the rotor adjacent the body includes respective annular galleries which communicate with the outlet of the pump through a passage including a filter, there being a portion of the passage extending substantiall radially within the rotor so that filtered liquid is supplied from the outlet of the pump to the galleries at a pressure in excess of the pressure in said chamber, thereby ensuring that, in use, there is a flow of filtered liquid from said galleries to said chamber to prevent ingress of dirt or grit from said chamber between said adjacent surfaces.

The accompanying drawing is a sectional view of a liquid pump, illustrating one example of the invention.

Referring to the drawing, the pump includes a body having therein a pair of cylindrical chambers 11, 12. The chamber 12, communicates with the chamber 11 through a pair of inlet passages 13 in the dividing Wall 14 between the chambers, and moreover the chamber 11 can be supplied with liquid through a supply passage 15 in the body 10. Extending axially within the body 10 and rotatable therein is a shaft 16 adapted at one end to be connected to a source of rotary motion. At its other end the shaft 16 has secured thereto a centrifugal impeller 17 rotatable within the chamber 11 and a rotor 18 rotatable within the chamber 12, the periphery of the rotor 18 ineluding a plurality of chevron shaped radial blades 19. The wall of the chamber 12 opposite the wall 14 has formed in it an annular channel, which is divided into two similar arcuate channels one of which is shown at 21, by a pair of similar and diametrically opposed fixed abutments one of which is shown at 22. Slidable axially within the annular channel is an annular piston 23 which is cut away at two angular positions adjacent the rotor 18 to accommodate the abutments 22 respectively.

The faces of the rotor 18 adjacent the walls of the cham ber 12 are formed with respective annular galleries 26, 27 which communicate with the other end of a substantially radial passage 28 within the rotor 18. The inner end of the passage 28 communicates with an axial bore 29 in the shaft 16 which itself communicates with an annular chamber 31 in the body 10.

The chamber 12 is provided with a pair of tangential outlet passages, one of which is shown at 32 through which liquid leaves the pump. The outlet passage 32 includes a filter element 33 which does not filter the main flow of liquid through the outlet passage 32, but which filters the liquid flowing through a side tapping 34 from the outlet passage 32. The tapping 34 communicates with the annular chamber 31 through a conduit 35 so that filter liquid is supplied to the chamber 31 at outlet pressure.

In use, liquid, for example fuel for a gas turbine engine, which may contain extraneous material such as dirt or grit is supplied to the chamber 11 through the passage 15.

Assuming that the fuel is dirty then as the shaft 16 is rotated the impeller 17 pumps the dirty fuel from the chamber 11 through the inlet passages 13 into the chamber 12 where it passes between the blades 19 and into the arcuate channels 21, 22. The rotation of the rotor 18 swirls the dirty fuel around the channels 21, until it impinges on the abutments 22 which direct the fuel back to the chamber 12 the rotor 18 then pumping the fuel from the chamber 12 through the outlet passages.

Some of the fuel passing through the outlet 32 is filtered by the filter element 33 and the resultant clean fuel flows through the conduit 35, the chamber 31, the bore 29 and the radial passage 28 to the galleries 26, 27. By virtue of the centrifugal action of the rotor 18 on the fuel in the radial passage 28 the clean fuel supplied to the galleries 26, 27 will be at a pressure in excess of the pressure in the chamber 12 and so clean fuel will flow from the galleries 26, 27 between the adjacent faces of the rotor 18 and the body 10 and into the chamber 12, thereby preventing dirt or grit, from the dirty fuel in the chamber 12 from entering between the adjacent faces of the rotor 18 and the body 10.

The annular chamber 31 extends through bearings 36 in which the shaft 16 is rotatably supported, thus the bearings 36 are supplied with clean fuel for lubricating purposes.

By varying the axial position of the piston 23 the volume of the channels 21, 22 is varied resulting in a corresponding variation in the output volume of the pump.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A liquid pump comprising a body, the body defining a chamber, a peripherally bladed rotor rotatably mounted in the chamber, said rotor having axially spaced side faces radially inwardly from the blades, an inlet and an outlet in the body communicating with the chamber, annular galleries in the side faces of the rotor respectively, adjacent the blades, a substantially radially extending passage in the rotor communicating at its outer end with the annular galleries, passage means affording communication between the outlet in the body and the inner end of said radially extending passage, and a filter in said passage means, whereas filtered liquid from the outlet flows from the annular galleries to prevent the ingress of foreign matter.

2. A liquid pump as claimed in claim 1 including a shaft connected to the rotor, bearings in the body in which the shaft is rotatably supported, and said passage means extending through the shaft, and a further passage affording communication between said passage means and said bearings.

3. A liquid pump comprising a body defining a chamber, a peripherally bladed rotor rotatably mounted in the chamber, at least one portion of said body having an annular recess in the side of the chamber at one side of the rotor, said recess provided with circumferentially spaced ends, an inlet and an outlet in the body communicating with the chamber at positions adjacent to the ends of the recess respectively, annular galleries in side faces of the rotor respectively at positions radially inwardly of the recess, a substantially radially extending passage in the rotor communicating at its outer end with the annular galleries, passage mean affording communication between the outlet in the body and the inner end of said radially extending passage, a filter in said passage means, and means for varying the volume of said recess in the body whereby the filtered liquid flows by centrifugal force through the annular galleries to prevent ingress of dirt.

'References-Cited' UNITED STATES PATENTS HENRY F. RADUAZO, Primary Examiner.

' US. Cl. X.R. 

